Intestine Homeostasis and the Role of Tumor Suppressor Gene 101 in Drosophila Melanogaster: A Dissertation

Tissue homeostasis in the adult Drosophila melanogaster intestine is maintained by controlling the proper balance of stem cell self-renewal and differentiation. In the adult fly midgut, intestinal stem cells (ISCs) are the only dividing cells and their identity maintenance is crucial to the proper functioning of the fly gut. Various pathways such as Notch, JAK-STAT and Wingless are known to regulate ISC division and differentiation. Here I used a pathogen feeding model to study conditions that accelerate ISC division and guide intestinal cell differentiation favoring enterocyte development. I also examined the role of Tumor Suppressor Gene 101 (TSG101) in ISC maintenance and function. TSG101, a part of the ESCRT1 complex. It is known to stimulate the Notch pathway and to play a role in endocytic trafficking. TSG101 loss-of-function mutants show developmental defects in various fly and mammalian tissues. The protein also plays a role in virus abscission from host cells. In my experiments I have observed that TSG101 is required for ISC maintenance. TSG101 knockdown and loss of function mutant clones have defects in ISC proliferation that hinder the normal intestinal responses to oral pathogen ingestion. Based on these results I conclude that TSG101 is needed in the adult fly intestine for proper ISC maintenance and function, thereby being an important player in intestinal homeostasis

INTERRELATIONSHIP OF STRESS, BODY IMAGE, NEGATIVE MOOD STATE AND SUSCEPTIBILITY TO ABNORMAL EATING BEHAVIOUR AMONG GAME SPECIFIC FEMALE ATHLETES: AN EXPLORATORY APPROACH

Purpose: To achieve and maintain a perfect body shape athlete often follows restrictive dieting which ultimately leads them to eating disorders. The purpose of the study was to identify whether there is an interrelationship of abnormal eating behaviours, perceived stress, negative mood state and self-perception of body image among athletic population and another was to observe the consequences of negative psychological well-being and game specificity on food choices and frequency. A secondary purpose of this study was to identify the “at risk-eating disorder” participants who were involved in different sports category. Methods: One thirty eight healthy young female participants matched for BMI were selected by purposive sampling. Subjects were divided into 4 categories i.e. aesthetic games group, endurance groups, strength group and healthy controls. Structured questionnaires were used for data collection during their non-competitive session. ANOVA followed by Scheffe’s test was applied to compare different parameters among the groups. Regression model examined the associations among disordered eating behaviours, stress, body shape concern, emotional eating, total mood disturbance and food choice. Findings: Result revealed disordered eating behaviour was significantly prominent in control and aesthetic game group than other two groups. Control group obtained the highest score in stress and emotional eating while aesthetic game group secured the highest score in body shape concern. Mood disturbance was more prevalent in strength group. Body mass index, body shape concern, emotional eating and total mood disturbance were identified as strongest predictor of EAT-26 scores. The result revealed that controls and aesthetic game group exhibit more abnormal eating behaviours than others. Value: This result will help to indicate abnormal eating behaviour and its relation with psychological well-being among female athletic population. Interventions programmes should be designed to cope up with competitive pressure to avoid abnormal eating behaviour.  Article visualizations

INTERRELATIONSHIP OF STRESS, BODY IMAGE, NEGATIVE MOOD STATE AND SUSCEPTIBILITY TO ABNORMAL EATING BEHAVIOUR AMONG GAME SPECIFIC FEMALE ATHLETES: AN EXPLORATORY APPROACH

Purpose: To achieve and maintain a perfect body shape athlete often follows restrictive dieting which ultimately leads them to eating disorders. The purpose of the study was to identify whether there is an interrelationship of abnormal eating behaviours, perceived stress, negative mood state and self-perception of body image among athletic population and another was to observe the consequences of negative psychological well-being and game specificity on food choices and frequency. A secondary purpose of this study was to identify the “at risk-eating disorder” participants who were involved in different sports category. Methods: One thirty eight healthy young female participants matched for BMI were selected by purposive sampling. Subjects were divided into 4 categories i.e. aesthetic games group, endurance groups, strength group and healthy controls. Structured questionnaires were used for data collection during their non-competitive session. ANOVA followed by Scheffe’s test was applied to compare different parameters among the groups. Regression model examined the associations among disordered eating behaviours, stress, body shape concern, emotional eating, total mood disturbance and food choice. Findings: Result revealed disordered eating behaviour was significantly prominent in control and aesthetic game group than other two groups. Control group obtained the highest score in stress and emotional eating while aesthetic game group secured the highest score in body shape concern. Mood disturbance was more prevalent in strength group. Body mass index, body shape concern, emotional eating and total mood disturbance were identified as strongest predictor of EAT-26 scores. The result revealed that controls and aesthetic game group exhibit more abnormal eating behaviours than others. Value: This result will help to indicate abnormal eating behaviour and its relation with psychological well-being among female athletic population. Interventions programmes should be designed to cope up with competitive pressure to avoid abnormal eating behaviour.  Article visualizations

Application of ImageJ for processing Shilajit exposed PBMC images

Objective: In this study, application of ImageJ for processing Shilajit exposed PBMC images were studied. Methods: In present study experiment was designed with human PBMC treated with Shilajit in high concentration (18mg/ml).Digital images were taken after one hour exposure with Shilajit and image processing steps were implemented. Results: Acquired images from Shilajit exposed human PBMC had low contrast and substantial background noise as media was mixed with Shilajit. So images were processed by adjusting brightness and contrast, applying median filter, thresholding and watershed algorithm. Conclusion: A high concentration of shilajit (18mg/ml) was detrimental to human PBMC. ImageJ can be efficiently used to process and extract information from low resolution images. Keywords: ImageJ, Shilajit, PBM

Alteration in Marrow Stromal Microenvironment and Apoptosis Mechanisms Involved in Aplastic Anemia: An Animal Model to Study the Possible Disease Pathology

Aplastic anemia (AA) is a heterogeneous disorder of bone marrow failure syndrome. Suggested mechanisms include a primary stem cell deficiency or defect, a secondary stem cell defect due to abnormal regulation between cell death and differentiation, or a deficient microenvironment. In this study, we have tried to investigate the alterations in hematopoietic microenvironment and underlying mechanisms involved in such alterations in an animal model of drug induced AA. We presented the results of studying long term marrow culture, marrow ultra-structure, marrow adherent and hematopoietic progenitor cell colony formation, flowcytometric analysis of marrow stem and stromal progenitor populations and apoptosis mechanism involved in aplastic anemia. The AA marrow showed impairment in cellular proliferation and maturation and failed to generate a functional stromal microenvironment even after 19 days of culture. Ultra-structural analysis showed a degenerated and deformed marrow cellular association in AA. Colony forming units (CFUs) were also severely reduced in AA. Significantly decreased marrow stem and stromal progenitor population with subsequently increased expression levels of both the extracellular and intracellular apoptosis inducer markers in the AA marrow cells essentially pointed towards the defective hematopoiesis; moreover, a deficient and apoptotic microenvironment and the microenvironmental components might have played the important role in the possible pathogenesis of AA

Primitive Sca-1 Positive Bone Marrow HSC in Mouse Model of Aplastic Anemia: A Comparative Study through Flowcytometric Analysis and Scanning Electron Microscopy

Self-renewing Hematopoietic Stem Cells (HSCs) are responsible for reconstitution of all blood cell lineages. Sca-1 is the “stem cell antigen” marker used to identify the primitive murine HSC population, the expression of which decreases upon differentiation to other mature cell types. Sca-1+ HSCs maintain the bone marrow stem cell pool throughout the life. Aplastic anemia is a disease considered to involve primary stem cell deficiency and is characterized by severe pancytopenia and a decline in healthy blood cell generation system. Studies conducted in our laboratory revealed that the primitive Sca-1+ BM-HSCs (bone marrow hematopoietic stem cell) are significantly affected in experimental Aplastic animals pretreated with chemotherapeutic drugs (Busulfan and Cyclophosphamide) and there is increased Caspase-3 activity with consecutive high Annexin-V positivity leading to premature apoptosis in the bone marrow hematopoietic stem cell population in Aplastic condition. The Sca-1bright, that is, “more primitive” BM-HSC population was more affected than the “less primitive” BM-HSC Sca-1dim  population. The decreased cell population and the receptor expression were directly associated with an empty and deranged marrow microenvironment, which is evident from scanning electron microscopy (SEM). The above experimental evidences hint toward the manipulation of receptor expression for the benefit of cytotherapy by primitive stem cell population in Aplastic anemia cases

Serum Contactin-1 in CIDP

To investigate whether serum levels of contactin-1, a paranodal protein, correlate with paranodal injury as seen in patients with CIDP with antibodies targeting the paranodal region. Serum contactin-1 levels were measured in 187 patients with CIDP and 222 healthy controls. Paranodal antibodies were investigated in all patients. Serum contactin-1 levels were lower in patients (N = 41) with paranodal antibodies compared with patients (N = 146) without paranodal antibodies (p < 0.01) and showed good discrimination between these groups (area under the curve 0.84; 95% CI: 0.76-0.93). These findings suggest that serum contactin-1 levels have the potential to serve as a possible diagnostic biomarker of paranodal injury in CIDP. This study provides class II evidence that serum contactin-1 levels can discriminate between patients with CIDP with or without paranodal antibodies with a sensitivity of 71% (95% CI: 56%-85%) and a specificity of 97% (95% CI: 83%-100%)

Plasma extracellular vesicle tau and TDP-43 as diagnostic biomarkers in FTD and ALS

Minimally invasive biomarkers are urgently needed to detect molecular pathology in frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). Here, we show that plasma extracellular vesicles (EVs) contain quantifiable amounts of TDP-43 and full-length tau, which allow the quantification of 3-repeat (3R) and 4-repeat (4R) tau isoforms. Plasma EV TDP-43 levels and EV 3R/4R tau ratios were determined in a cohort of 704 patients, including 37 genetically and 31 neuropathologically proven cases. Diagnostic groups comprised patients with TDP-43 proteinopathy ALS, 4R tauopathy progressive supranuclear palsy, behavior variant FTD (bvFTD) as a group with either tau or TDP-43 pathology, and healthy controls. EV tau ratios were low in progressive supranuclear palsy and high in bvFTD with tau pathology. EV TDP-43 levels were high in ALS and in bvFTD with TDP-43 pathology. Both markers discriminated between the diagnostic groups with area under the curve values &gt;0.9, and between TDP-43 and tau pathology in bvFTD. Both markers strongly correlated with neurodegeneration, and clinical and neuropsychological markers of disease severity. Findings were replicated in an independent validation cohort of 292 patients including 34 genetically confirmed cases. Taken together, the combination of EV TDP-43 levels and EV 3R/4R tau ratios may aid the molecular diagnosis of FTD, FTD spectrum disorders and ALS, providing a potential biomarker to monitor disease progression and target engagement in clinical trials.</p